Knife edge seals are used in most rotors of a gas turbine engine to prevent gas from leaking around rotors and blades. Knife edge seals are particularly used in very hot areas, such as the high pressure compressor and high pressure turbine. A typical knife edge seal is a full hoop with a portion attaching to a rotor or blade and a knife edge which contacts another rotor, blade, casing or other part to prevent leakage.